During The Cardinal Nation’s top 40 Cardinals prospects countdown for 2010, I have been troubled by what I perceive to be a recurring theme. A number of the Cardinals minor league batters don’t seem particularly well-suited to the more challenging defensive positions, leaving the organization with a glut of hitters and limited places to play them.

As likely the case in many organizations, players are challenged to master the most difficult positions possible, but the Cardinals seem to be doing it more often and less successfully than others. As such, the current Cardinals system appears to be deploying more than its share of “natural” first basemen at third base and the corner outfield positions, corner outfielders in centerfield, second basemen at shortstop, and any player whatsoever at catcher.

In an attempt to test this theory, I needed a way to assess defensive metrics across the Cardinals system relative to their peers. Unfortunately, there isn’t much minor league fielding data out there for the taking, but MiLB does provide team-by-team run and earned run tallies. This allows us to evaluate unearned runs against the league average.

I certainly won’t claim that team unearned runs are the ideal measurement of fielding prowess, but they do provide one valid basis for comparison. I’m going to use the term “uERA” to represent a club’s unearned run average – the number of unearned runs allowed every nine innings. The following table compares the uERA of the Cardinals’ affiliates at each level of play to the rest of their league:

Table: 2009 Unearned Run Data

Team

League

League uERA

Team uERA

Rank

St. Louis

MLB

0.35

0.34

15 of 30

Memphis

Pacific Coast League (Triple A)

0.49

0.54

12 of 16

Springfield

Texas League (Double A)

0.67

0.66

4 of 8

Palm Beach

Florida State League (Class A Advanced)

0.69

0.78

11 of 12

Quad Cities

Midwest League (Class A)

0.71

0.86

10 of 14

Batavia

New York-Penn League (Class A Short Season)

0.85

0.84

9 of 14

Johnson City

Appalachian League (Rookie)

0.91

1.14

10 of 10

GCL Cardinals

Gulf Coast League

0.97

1.22

14 of 16

VSL Cardinals

Venezuelan Summer League

1.17

1.08

8 of 33

DSL Cardinals

Dominican Summer League

1.43

1.22

3 of 7

I find it particularly interesting that in 2009, every level of play in the US had a lower uERA than the one below it, reflecting expected defensive improvement as players gain experience. The Single A Midwest League yielded twice as many unearned runs per game as the major leagues and the Gulf Coast League gave up just shy of three times as many as MLB.

Of the US-based teams, only Springfield and Batavia (along with the major league Cardinals) managed league-average marks, while the other five affiliates allowed significantly more unearned runs than their league competitors. The Venezuelan and Dominican Cardinals both yielded far fewer unearned runs than league average, though one could only expect a relative handful of those players to even advance to play in the United States.

Although the upper levels of the Cardinals minor league system did skew younger than their competition this past season, there has to be some real concern over whether the organization will be able to supply enough major league-quality defenders in the years to come, the way that they have in recent seasons with Yadier Molina, Brendan Ryan, and Colby Rasmus.

While the current batch of Cardinals prospects may project to be adequate corner infielders and outfielders, there may be an especially noticeable dearth of quality prospects up the middle with standout offensive and defensive skills. The value of these types of players in St. Louis is even higher when paired with the Dave Duncan ground ball-oriented pitching focus.

With Albert Pujols hopefully slated to man first base for many seasons into the future and no designated hitter available in the National League, the Cardinals need to focus on acquiring and developing prospects who can field at an appropriate level to support their pitching philosophy. Offensive prowess alone is not enough.